Mixing element



FIG. 1 is a perspective view of a new design for a mixing element;

FIG. 2 is a back view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a side view thereof; and,

FIG. 5 is a top view thereof.

The broken lines in the drawing views are included for the purpose of illustrating portions of the mixing element that form no part of the claimed design. 

CLAIM The ornamental design for a mixing element, as shown and described. 